Sheet feeding apparatus



- 1 cub. KNOWLTON 'SHEET FEEDING APPARATUS Fired June 19, 1940 9 Sheets-Sheet 1 'MZM- Nov. 10, 1942.

c. D. KN OWLTON SHEET FEEDING APPARATUS 9 Sheets-Sheet 3 Filed June 19, 1940 Nov. 10, 942-- c. u. KNOWLTON SHEET FEEDING APPARATUS I Filed June 19, 1940 9 Sheets- Sheet 4 10, 1.94 'c. 0. KNOWLTON 2,301,214 v SHEET FEEDING APPARATUS Filed June 19, 1940' 9 Sheets-Sheet 5 N/ENTUR:

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Nov. 10, 1942. LT 230L214 SHEET FEEDING APP'ARATUS I Filed June 19, 1940 9 Sheets-Sheet 7 Fig". 23

M 10, 19 c. D. KNOWLTON SHEET FEEDING APPARATUS Filed June 19, 1940 9 Sheets-Sheet 9 Patented Nov. 10, 1942 2,301,214 SHEET FEEDING APPARATUS Cutler D. Knowlton, Beverly, Mass., assignor to Hoague-Sprague Corporation, Lynn, Mass., a corporation of Massachusetts Application June 19, 1940, Serial No. 341,326

76 Claims.

This invention relates to a sheet feeding apparatus and is herein illustrated and described as embodied in a mechanism for feeding box and box cover blanks to an apparatus for operating on such blanks. The invention is not limited, however, to use in box making machinery but may be employed to equal advantage in any apparatus for receiving sheets and delivering them one at a time to operating means.

It is an object of the present invention to provide for the rapid and eflicient handling of a number of packs of sheets of difierent sizes and to insure that they will be successively presented in proper position to a device which picks off the sheets one at a time and presents them to delivery means or other apparatus. Accordingly, the invention provides a conveyor mechanism upon which the blanks are supported on edge in groups or packs, these packs being held in spaced relation to one another on the conveyor until such time as they are inserted in a magazine at the delivering end of the conveyor. Spacing of the packs is accomplished by the provision of a number of pack supporting members which form a part of the conveyor mechanism and have the dual functions of separating the packs and of transmitting to the packs the movement of the conveyor mechanism toward the magazine. Provision is also made for shifting these pack engaging members from pack supporting position at or near the end of their movement toward the magazine, and for moving them into pack engaging position at the opposite end of the conveyor.

A further object of the invention is to insure the certain and rapid removal of successive single sheets from the magazine. Provision is therefore made for suction members adapted to bend or roll the bottom edge of the forward sheet in the magazine away from the stack therein. When the edge of the sheet has been so rolled, away from the stack, a separator or shuttle moves upwardly to complete the separation of the sheet from the stack. means for engaging the upper edge of the sheet, thereby enabling the separator, as it returns to its original position, to carry the sheet downwardly into a position where it may be engaged by delivery mechanism.

Another object of the invention is to control the feeding movement of the conveyor in such a manner that it will always maintain an adequate supply of sheets in the magazine from which the picking means removes single sheets. In accordance with this object, provision is made for advancing the conveyor at two different 55 This separator is provided with speeds. The high speed conveyor advancing mechanism is arranged to operate only when there is a gap between the rearmost sheet in the magazine and the foremost sheet in the next succeeding pack which is about to be inserted in the magazine. The low speed conveyor advancing mechanism is controlled by the picker means in such a manner that when the picker means must advance into the magazine beyond a predetermined point in order to grip the leading sheet, the low speed conveyor advancing means is started and continues to operate until the supply of sheets in the magazine has been replenished. A further object of the invention is to provide means whereby a predetermined number of sheets may be run through the machine, and upon the movement of the last sheet through the machine, the feeding mechanism will be rendered inoperative. To this end, there are provided a register for indicating the number of sheets that have passed through the machine and mechanism controlled by the register for shutting off the suction in the suction members after the requisite number of sheets have been fed thereby.

Obviously, it is desirable to produce an equal number of boxes and covers. For this reason the box making machinery and the cover making machinery are advantageously operated as'two sections of a single unit. Consequently, there are two substantially identical feeder mechanisms, one for boxes and one for box covers, and it is, accordingly, a further object of the invention to provide means for insuring that the two feeding mechanisms will each feed the same number of box blanks and cover blanks. In the attainment of this object, I have provided mechanism for controlling the amount of suction in the suction members of the picking means in such a manner that if the suction member of one feeder picks up a blank but that of the other feeder fails to do so, the vacuum in the member holding the blank will be insuflicient for the member to maintain its grip on the blank and it will thereupon release it.

picking and delivering portion of the machine of Fig. 1;

Fig. 3, a plan View of the portion of the machine illustrated in Fig. 1;

Fig. 4, a section along the line IVIV of Fig. 1;

Fig. 5, a detail side view of the upper portion of the magazine;

Fig. 6, an enlarged plan View of the portion of the machine illustrated in Fig. 2, parts of the mechanism being broken away;

Fig. 7, a detail plan view of the means for centering the blanks;

Fig. 8, a broken elevation of the clutch connecting the high and low speed conveyor drive motors;

Fig. 9, a section along the line IX-IX of Fig. 8;

Fig. 10, a detail of the rod lowering mechanism from a point indicated at x on Fig. 1;

Fig. 11, an enlarged view in broken side elevation of the mechanism for separating the forward sheet from the stack in the magazine;

Fig. 12, an elevation looking from the right in Fig. 16, a plan view of the parts shown in Fig.

Fig. 17, an elevation of the switch mechanism for the low speed conveyor motor;

Fig. 18, an end elevation of the mechanism of Fig. 17;

Fig. 19, a side elevation of the shear pin stop mechanism;

Fig. 20, a section along the line XX-XX of Fig. 19;

Fig. 21, a section along the line XXL-XXI of Fi 6;

Fig. 22, an elevation of the counter mechanism;

Fig. 23, a side elevation of the mechanism for detecting jams in the magazine; and

Fig. 2 1 is a wiring diagram of the machine.

As has already been pointed out, the embodiment of the invention shown in the drawings for purposes of illustration is a feed mechanism for a box making machine. This machine bein adapted to manufacture boxes and covers, there will, of course, be two feed units, one for the covers and one for the boxes. Inasmuch as these two feed units diifer from each other only in certain particulars, which will hereinafter be pointed out, only one feed unit has been illustrated.

In order to aid in understanding the invention, the illustrated machine will be described generally first, and then the separate sections will be taken up in detail.

General description Referring now to Figs. 1 and 2, the machine may be divided, roughly, into three sections,-a conveyor mechanism, generally designated at A, which holds on edge a number of separate packs of blanks X having corner laps L and end wings W (Figs. 15 and 16) and carries them to a magazine B; a picker mechanism, generally indicated at C, for separating a single sheet from the stack in the magazine; and a delivery mechanism D, which picks up the blank presented to it by the picker mechanism and carries it to the machine where it is made into a box-part. The conveyor mechanism A comprises a framework 5!! to which is secured a table 52 upon which the blanks rest between opposite guide-walls 54. Movement of the packs of blanks over the table toward the magazine B is effected by a number of vertical rods 56 which act as supports to hold the packs in upright position and keep them separate, these rods being slidably carried in conveyor chains 58. Upon arrival at the magazine, the rods are moved downwardly out of pack supporting position by lever mechanism 60 which simultaneously lifts rods at the opposite end of the conveyor into pack supporting position.

Situated on the opposite side of the magazine B from the conveyor mechanism is the picking mechanism C comprising a picker arm 62 mounted for swinging movement about a shaft 64 and carrying a presser foot 66 and suction cups 68. The actuating mechanism for the picker arm is such that the presser foot and the suction cups are moved toward the leading blank in the magazine in approximately heightwise alinement. As these members engage the leading blank, the suction cups become effective to grip the lower edge of the blank and then, while the main portion of the blank is held in place by the presser foot, to swing said edge forwardly away from the stack in the magazine. When the blank has been thus bent, a pair of shuttles or separators To move upwardly between it and the remainder of the stack to complete the removal from the magazine.

The shuttles are provided with catches 12 which engage the top edge of the blank and, when the shuttles return to their starting position, slide the blank downwardly between carrier wheels M and curved guides 16. The carrier wheels are provided with lugs 1'8 traveling in timed relation to the shuttles, so they will engage the upper edge of the blank to continue its advance. After having been carried through approximately a half revolution by the wheels, the blank enters between a second set of guides. and a set of sprocket wheels 82 driven by chains 84. These chains are provided with lugs 86 which engage the edge of the blank and carry it up over the wheels 82 and between hold-down bars 90 and parallel horizontal rails 88 alon which it is advanced by the chains to the operating mechanisms of the machine.

Conveyor mechanism and magazine Returning now to the conveyor section A of the machine, the table 52 is divided into three parts, a center section 92 (Fig. 3) and opposite side sections 94, 9B. Adjacent to the outer edges of the side sections 94 there are provided a series of brackets 96 to which angle irons I00 are secured by screw-and-slot connections 98. The guide-walls 54 are fastened to the vertical portions of these angle irons, so that by loosening the connections 98 they may be adjusted to the correct relation to each other and to the magazine B. To the forward end of each of the walls 54 is secured an upstanding support H32 and to this support, as shown in Fig. '7, is fastened a centering finger HM. This centering finger, which is preferably of a somewhat resilient metal, is inclined toward the center section 92 of the table, extending inwardly slightly beyond the inner face of the wall so that it exerts pressure upon the blanks and positions them transversely as they enter the magazine.

The magazine B is provided With'means forholding the blanks in upright position parallel to one another in proper relation to the picking mechanism. To this end, dogs I06 (Figs. 1, 2 and are provided at the top and bottom of the magazine. The forward faces ID! of these dogs are fiat and provide a surface against which the blanks are urged at their top edges by a hooked end I08 of a leaf spring IIO bolted to a bridge bar I I2 secured to uprights II3 of the frame. At the bottom edges of the blanks, there is a retaining member II4 secured to a rod II6 slidable longitudinally of the table in a boss I I8. This retaining member is movable in a slot in the table and is urged rearwardly by a spring I20 surrounding the rod, thus holding the pack of blanks in the magazine tightly against the dogs I 66. Forward displacement of the blanks at their top edges is limited by stops I30 on blocks I32 adjustably fastened to the frame by screw-and slot connections I34. The stops, the end of the spring IIO, the retaining member H4, and the dogs I06 cO-Operate to hold the blanks upright in the magazine, close against one another, in a predetermined relation to the picking mechanism C.

To permit the blanks to be fed into the magazine,.the dogs I06 have their rearward faces beveled at I2I (Fig. 5) and are pivoted at I22 in blocks I24 adjustably secured to a crossbar I25 of the frame by screw-and-slot connections I26. The dogs are urged into the path of the blanks by spring-pressed pins I28 and thus, when a stack of blanks is being moved forwardly into the magazine, the dogs will be forced aside by their upper and lower edges, and when the entire pack has been fed into the magazine, the dogs will drop down and prevent the blanks in the magazine from falling rearwardly.

Between the rods 56 of the conveyor mechanism, the operator may insert separate packs of box-blanks of any given number in one section 94 of the machine and like packs of cover blanks in the other section. If a number of orders of different magnitudes are being filled, this arrangement facilitates the handling of the packs of blanks, enabling them to be inserted in the machine and kept separate for the operations upon them. The rods of each section travel in pairs under the influence of the chains 58. At regular intervals along these chains there are special guide links I36 (Figs. 3 and through which the rods may be slid longitudinally without disturbing the movement of the chains. These chains operate in pairs, one pair on each side are secured to a vertical shaft I40 journaled in' the frame. At the rear end of the conveyor the chains pass over similar sprockets I42 secured to short shafts I44 journaled in bearings I46 formed in blocks I48 secured to uprights I43 of the frame by screw-and-slot connections I50. By loosening these connections, the blocks may be shifted horizontally to regulate the tension on the chains. Rotation of theshaft I40 and sprocket gears I38 and. I42 will cause the chains to carry the rods 56 toward and away from the magazine, the inner runs adjacent to the center section 92 of the table traveling toward the magazine.

' tion on the upper rail I52.

To hold the slidable rods in an upper or packseparating position, a rail I52 is secured to the frame beneath the inner runs of the chains. A base I 54 (Fig. 10) is threaded onto the lower end of each rod and secured by a nut I56. Thus, a rod moving toward the magazine is held in pack supporting position by the rail I52.

As each rod reaches the magazine, it is moved out of pack separating position for its return to the loading end of the conveyor. This is accomplished by causing the rod to be lowered until its top is below the table 52, Since the rail I52 is directly beneath the inner run of the chain, as the chain reaches the sprocket I33 and begins to move about it, the rod will be carried off the rail, Where it is free to drop under its own weight, in a direction substantially parallel to the rear face of the sheets in the magazine B, to a lower rail I53, along which it may travel back to the loading end of the conveyor in lowered position. It may sometimes occur that the pressure of the pack of blanks against the rods is suihcient so the rods will not drop by gravity. To insure that the rods will be fully retracted and not strike the guideways 54, there is provided the lever 60 (Figs. 1, 3 and 4) which is pivoted approximately at the center of the machine on a shaft I60 journaled in uprights I62 bolted at I64 to the frame. At the magazine end I65 of the lever are two links I68 (Fig. 10) pivoted on a cross pin I10 carried by the lever. The other end of each link is connected by a pin II'Z to a slide I14, movable vertically on a rod I'IS secured to the rame. At the lower end of the slide is a threaded stud I18 to which a finger I82 is secured by a nut I85 and beneath the end of which the rod-bases I54 travel. Movement of the lever 66 is so timed relative to the movement of the chain that as the rod is shifted oif the rail I52, and the end I06 of the lever is swung downwardly, the finger engages the base and forces the rod down to the level of the lower rail I58.

As each of the rods 56 reaches the rear or loading end of the conveyor, it must be raised from the lower rail I53 to pack engaging posi- To accomplish this, the lever 60 has at its rearward end I34 two links I 85 (Figs. 1 and 4) pivoted to it by a cross pin I83. The other end of each link I 85 is pivoted to a slide I movable on a vertical rod I92 secured in the frame. To the lower end of the slide I95 is secured a table I94 above which the base of the rod 55 is moved as said rod begins its travel about the sprockets M2. With the rod above the table, the lever 85! is swung about the shaft. ISQ by mechanism, hereinafter to be described, so as to lift the rod into a position such that as it travels about the sprockets IQZ it will move onto the rail I 52. The rods are thus successively raised and lowered for their pack-advancing travel and idle return movement.

The chains 58 are driven by worm gears I98 (Figs. 1 and 4) secured to the lower ends of the vertical shafts I40. The worm gears mesh with worms I98 fast on a shaft 225 journaled in the frame and having secured thereto a sprocket gear 202 over which passes a drive chain 254. This chain also passes over two other sprockets ace and 298 and a tightening idler gear 2 I0 journaled on a spindle 2I2 carried in a slot 2I4 in a boss 2I6 on the frame. Adjustment of the tension of the chain 204 is effected by loosening a nut 2I3 threaded on the end of the spindle 2I2, thus enabling the spindle 2I2 to be shifted in the slot 2 4.

Swing movement of the lever 68 is effected through a crank wheel 238 fast upon a shaft 232 and linked to the lever by a connecting rod 228. This rod comprises an end member 222 pivotally connected to ears 224 on the under side of the lever, the rod being threaded into the end member 2212 so that the length 'of said rod may be adjusted and held in position by a nut 228. The end 226 of the connecting rod is pivoted to the crank wheel 238, which is mounted. on a shaft 232, and has secured to it a pair of drive'members 234. At the opposite sides of each drive member are slots 238 adapted to receive one of two pairs of rolls 238 projecting oppositely from the chain 284. It will be noted that as the chain 284 travels from the sprocket 288 to the sprocket 286 it passes over a roll 238 which is secured to the shaft 232 between the drive members 234. This roll 238 so guides the rolls 238 that they will be carried into the slots 238 and cause the crank wheel 238 to rotate contraclockwise (Fig. 1). After half a revolution of the crank wheel has raised the end I84 of the lever 88, the rolls are at the top of the guide roll 238 in position to leave the slots 238.

To insure that the crank wheel will stop in proper positions for the rolls to enter and leave the slots in the drive member, a spring-pressed detent pin 248 is mounted on the upright I82 adjacent to the crank wheel, When the pin is in a notch 242 in the periphery of the crank wheel, the lever is at either the top or the bottom of its movement and the slots 238 are in vertical alinement with one another so that the rolls may readily enter or leave the slots.

The ratios of the various gears and sprockets are such that the chain 284 makes one complete revolution during the period that the chains 58 travel a distance equal to the space between two adjacent rods 56. Thus, as the next rod approaches its elevating position, the end I84 of the lever 68 will be swung down to its receiving position. The rod-shifting movement of the lever occurs shortly after the rod at the magazine has moved off the rail I52 and the rod at the loading end of the conveyor has moved over the table I94. The return movement of the lever will occur when the chains 58 have traveled approximately half the distance between rods. There is thus allowed the proper time for the chains 38 to carry the rod at the magazine end onto the rail I58 and to carry the rod at the loading end of the conveyor onto the rail I52, and for the lever-ends I66 and I84 to return to their starting positions. Therefore, as the next rod at the magazine end moves off the rail I52, the finger I82 will be above the base of the rod in position to force it downwardly. Similarly, the table I94 will be in elevating position below the base of the rod at that end of the conveyor.

Driving of the conveyor and of the lever is effected through a sprocket 243 (Figs. 1 and 5) mounted on a shaft 244 upon which the sprocket 288 is secured. A chain 246 passes over the sprocket 288 and over a sprocket 248 keyed to a shaft 258 connected to a reduction gearing 252. Power to operate the reduction gearing is supplied by a pair of motors 254, 256 respectively, in a manner hereinafter to be described.

Picker mechanism The blanks having been brought to the magazine and inserted therein in a horizontal stack, i. e., on edge with their side faces substantially vertical, they are removed from the magazine B one at a time and presented to the delivery means by the picker mechanism C illustrated in Figs. 2, 1'1, and 12. Secured to the uprights II3 of the frame is a horizontal crossbar 258 to which hangers 268 are bolted, these furnishing bearings for the shaft 64. Rotatable about the shaft is a sleeve 262 and to this sleeve the picker arm 62 is clamped at 264. To the picker arm the presser foot 66 is pivotally connected at 266. The presser foot has an extension 268 in which a pipe 218 is clamped at 212. The suction cups 6B are clamped to the ends of the pipe on either side of the presser foot, passageways 214 in cup mountings 215 connecting the cups to the pipe. An arm 216 is clamped at 288 to the shaft 64 by a bolt 218, the other end of the arm being pivotally connected to a link 282. The link is pivotally connected at 284 to a yoke 286 upon the presser foot extension 268. By this arrangement relative movement of the sleeve 262 and the shaft 64 causes the presser foot and the suction cups to swing about the axis of the pivot 263.

To effect such relative movement an arm 288 is secured to the end of the shaft 64, this arm being connected by a link 298 to a bell crank lever 292 (Figs. 2, 6 and 14) pivoted on a pin 294 journaled in a bearing member 298 secured to a bar 298 of the frame. An arm of the bell crank carries a roll 388 which rides in a cam groove 382 in the side of a ear 384 keyed to a shaft 386 journaled in the frame, and driven through connections (not shown) to a motor 381 (Fig. 24)

A similar arrangement is provided for the sleeve 262. This mechanism comprises an arm 388 fastened to the sleeve 262 and pivotally connected to a link 3|8. The opposite end of the link extends through a boring in a connecting pin 3I2 (Figs. 6 and 13) turning in a forked arm 3 I4 of a bell crank 3| 6. A shoulder 3|8 is formed on the rod 3|8 and a spring 328 surrounding the rod between the shoulder and the pin provides a yieldable connection between the rod and the bell crank, so that if the presser foot 66 strikes the pack of blanks in the magazine before the arm of the bell crank has completed its rearward movement toward'the magazine the rest of the movement will be taken up by the spring. A nut 322 threaded onto the end of the rod 3|8 assures that the bell crank will pull the link rearwardly upon return to its initial position. The bell crank is pivoted at 324 to a bracket 326 secured to a crossbar 328 of the frame and carries on its other arm 338 a cam roll 332. This cam roll operates in a cam groove 334 out in the side of a disk 336 secured to the shaft 386 by a key 338, and providing operating mechanism by which the picker arm 62 is swung toward and from the magazine. The configuration of the cams 334 and 382 is such that the presser foot 66 and the suction cups 68 are swung in toward the magazine in substantially heightwise alinement, that is, in the position shown in Fig. 2. When they have made contact with a blank, the suction cups are caused to grip the bottom edge and pull it forward over the edge of the retaining member I I 4 to the position shown in Fig. 11. As the lower edge of the blank is rolled outwardly, it is also drawn downwardly away from the hook I88, so that it is free to be moved away from the remainder of the pack by the separator 18.

To create suction in the cups 68, one end of the pipe 218 is connected by a flexible hose 348 (Figs. 2 and 24) to one side of a manually operated shut-off valve 342'. The opposite side of this valve is connected through a cam-actuated piston valve 344 (Fig. 13) to a suction pump (not shown). The piston valve 344 comprises a cylinder in which a piston 346 is slidable and is so arranged that in its upmost position the suction valve is closed. The piston is pivotally connected to a link 348, the opposite end of which is slotted to receive a bolt 350 by which it is adjustably connected to a lever 352 pivoted in an ear 354 on the frame ofthe machine. The opposite end of the lever 352 carries a cam roll 356 which is held against a cam surface 358 of the cam disk 336 by a spring 363. This cam surface is so shaped at 368 that the valve 344 is opened as the suction cups engaged the forward blank in the magazine and then, as the cups are swung away, the valve is partially closed.

As has been pointed out, the machine is built in two parts, one for boxes and one for box covers. The mechanism for opening and closing the air suction valve is common to both parts, the suction cups of each being connected to the valve 344 on the side away from the suction pump, as shown in Fig. 24. The reduction in the suction by partial closure of the valve is such that unless the suction cups of both sides of the machine have gripped the blanks, the leakage at the pair which failed will be so great that those on the other side of the machine will not retain sufficient vacuum to hold the sheet. By this arrangement, it is made certain that an equal number of box and cover blanks will be fed.

To complete the separation of each blank from the stack and to move it out of the magazine, the separators T8 are provided. These separators, two in number in the illustrated machine, are secured to laterally extending rods 362 (Fig. 2) which at their ends are fastened to slides 364. The slides are movable vertically upon rods 366 held by set screws 368 in collars 310 bolted to the frame. The movement of the slidesis effected through a lever 3'42 pivoted at 314 in a framebracket 316. The forked end 318 of the lever is pivotally connected to the end 383 of a link 382, the length of which is adjustable. The opposite end of the link is pivoted to an ear 334 upon one of the slides 364. Movement of the lever 312 is accomplished through a crank 366 linked by a connecting rod 383 to the lever at 336. The crank 336 is keyed to a shaft 392 journaled in a bracket 394 secured to the frame. This shaft 392 is driven by a gear 396 which meshes with the gear 343 on the shaft 366. The ratio of the gears 366 and 364 is 1 to 2 so that the lever 312 reciprocates the separators twice during a single revolution of the shaft 366, the cams 362, 334, and 358 being so formed as to cause the picker mechanism to perform two complete cycles for each revolution of the cams.

As the separators travel upwardly, their upper ends, which are slightly pointed to enable them to separate the leading blankfrom the pack in the magazine, complete the separating action begun by the presser foot and the suction cups and move the blank to the position shown in Fig. 11 in dotted lines for presentation to the delivery means. Each separator is provided with the catch 12' formed on one end of a member 466 pivoted at 398 in the separator and projecting outwardly to engage the edge of the sheet. Forward movement of the catch 12 is limited by 2. lug 462 which strikes against the inside of the hollow end of the separator. A spring 464 between the separator and a lug 466 on the member 480 holds the catch in sheet engaging position but permits it to be forced inwardly as the separator moves upwardly and the catch strikes the rear face of the blank being separated from the stack. With the face of the catch 32 in engagement with the top edge of the blank, the separator is ready for its return movement to carry the blank to the delivery means, a number of guides 468 secured to the frame being provided to hold the blank in position to be engaged by the catch.

To aid the separator in separating the leading blank from the stack on the box side of the machine, there are provided bridge bars 4H1 (Figs. 15 and 16) which connect the upper end of the separator and the rod 362 and thus prevent the ends of the blank, if they are warped forwardly, from catching on the rod 362 and thus causing the machine to jam. Further to assist in preventing the blanks from jamming, the end wings W of the box blanks X are inclined slightly rearwardly by stops 4l2 secured to the frame and against which they are pressed by the conveyor mechanism. When the leading blank is slid downwardly slightly by the rolling action of the suction cups and the presser member, the corner lap L of the leading box blank will not catch on the edge of the end wing W of the next succeeding blank as might be the case were the end wings not thus bent.

Delivery mechanism To carry the blank from the picker to the operating means of the machine, the delivery mechanism is provided. Presentation of the blank to the delivery mechanism is effected by the downward movement of the separators in. As the blank moves downwardly, its lower edge slides between the carrier Wheels 14 and the arcuate guide bars '16 (Figs. 2 and 6). The wheels 14 are keyed to a shaft M6 journaled in the crossbar 293 of the frame and driven by a gear 4M meshing with the gear 364. Support for the guide bars 15 is provided by a bracket 4! bolted to an upstanding lug 420 of a crossbar 422 of the frame. Rods 424 secured in the bracket 4l8 extend through the guide bars which are held in place thereon by set screws 426 (Fig.2). As the shuttle continues its downward movement, the blank is carried to a position where its top edge may be engaged by the lugs 18 of wheels 14. End guides 428 secured to the rods 424 insure that the blank will not move endwise as it travels about the carrier Wheels 14. After the blank has completed approximately half a revolution on the carrier wheels 14, its top edge is engaged by the lower ends 436 of the guide bars 83, These guide bars are mounted on rods 432 secured to the frame by a hanger 434, the central portion 436 (Fig. 21) of which serves as a supplementary guide to prevent the central portion of the blank from buckling outwardly away from the shaft 366 as it passes over the wheels.

As the stripping of the blank from the carrier wheels-I4 nears completion, its lower edge is engaged by the lugs 86 carried on the chains 84. These lugs carry the blank about the carrier wheels 82 and up onto the rails 88. The chains 84 pass over sprocket wheels 438 keyed to the shaft 306, these wheels being of slightly smaller diameter than the carrier wheels 82 to insure that the lubricant on the chains 84 will not get onto the blank being fed. The blank is now in position to be carried between the rails 88 and the hold-downs 953, to the operating mechanism of the machine. The rearward ends of the rails are provided with fingers 443 (Fig. 21) which separate the blank from the carrier wheels 82.

Conveyor driving mechanism The normal rate of advance of the blanks into the magazine is preferably only slightly faster than the rate at which they are withdrawn by the picker mechanism. In order to close the gaps between the packs of blanks as they are about to be fed into the magazine B, the conveyor must be advanced somewhat more rapidly. To meet these requirements, it is necessary to operate the conveyor at two different rates of speed and for this purpose the motors 254 and 256 are provided, the motor 256 being arranged to drive the conveyor at a slow rate of speed and the motor 254 at a higher rate. Referring now to Figs. 8 and 9,

the slow speed motor 256 is provided with a pulley 7 442 secured to a motor shaft 444 and arranged to drive a belt 446 which passes over another pulley 446. Thepulley 448 is of substantially larger diameter than the pulley 442 and is mounted on ball bearings 456 for free rotation about a bushing 452 keyed to a motor shaft 454 of the high speed motor. Rings 456 carried by ballbearing raceways 458 hold the pulley 448 in position later-ally, The bushing 452 is provided with a flange 466 on its inner end and is threaded at its outer end to receive a nut 462 which holds a clutch plate 464 in position on the shaft. A looking washer 466 is provided for the nut 462.

Secured to the periphery of the clutch plate 464 by screws 468 is a pawl carrier 410 having a number of pairs of ribs 412 upon its side face. These ribs form guideways for pawls 414 which are urged inwardly toward the axis of the shaft 454 by springs 416 and are provided with "teeth I 418 which, when the mechanism is at rest, engage teeth 480 of a clutch ring gear 482 secured to the pulley 448 by screws 484. By this arrangement, when the slow speed motor is running, it drives the large pulley 448, and the clutch ring gear 482, and the pawls 414 carried by the clutch plate 464 drive the motor shaft 454 which is connected to the reduction gear 252. When the high speed motor 254 is in operation, however, and this may occur regardless of whether or not the slow speed motor 256 is running, the clutch plate 464 is rotated at a much more rapid rate than it would be if driven by the pulley 443. This relatively high speed sets up a centrifugal force which causes the pawls 414 to move out- I wardly against the springs 416, thus disengaging the pulley 448 driven by the slow speed motor 256. When the high speed motor shuts off, the clutch plate decelerates until its speed is equal to that of the pulley 448, at which time the springs 416 overcome the decreased centrifugal force and move the pawls into engagement with the clutch gear teeth 486.

To start the high speed motor 254, when there is a space between the foremost. blank of the pack about to be fed into the magazine B and the rearmost blank in the magazine, a gap detector is provided. This comprises a spring finger 486 (Figs. 2 and 5) secured to a portion of the cross bar I25 and depending in the path of the advancing blanks to such a distance that it will be raised by the pack of blanks being fed into the magazine. The finger is provided with a horizontal portion 488 which engages a push button 49!! of a switch 462 connected to the high speed motor. This switch is so arranged that pressure upon the push button opens the switch, thereby shutting off the high speed motor 254. Upon release of the button, the switch closes, and when the finger is freed by the blanks, the high speed motor is started and continues to operate until the conveyor has closed the gap behind the magazine and again raised the finger.

Mechanism is also provided for intermittently operating the low speed motor 256 of either the box section or cover section. To this end, a mercury switch 494 (Figs. 17 and 18) is mounted on a block 495 pivoted on a screw 466 for tilting movement in a switch box 453 secured to the frame. At the rear of the switch box a rod 562 is movable in a guide 566. The lower end of this rod carries a pin 564 on which is pivoted a lever 566 held in place by a spring 563 and a nut Elil. Each end of the lever is secured to one of a pair of switch rods 5l2, 5l3 which extend upwardly and are slidable in eyes 5M on the switch block 495. The rods are each provided with heads 5l6 so that when both heads are in contact with the eyes upward movement of either one of the switch rods operates the lever 566, lowering the opposite switch rod and tilting the switch 494 to open or closed position. The switch is held in the position to which it is moved by a springpressed pin 5H carried in a bore in the block 495.

Control of the switch is effected by positioning the switch rods 5l2, 513 directly over the link are connecting the picker arm sleeve 252 to its oper ating cam 334 (Figs. 2 and 13). The link 3) is provided with a pair of collars 548, 519 which are clamped thereto with screws 526. Blocks 522 and 523 are respectively pivoted at 524 to the collars 5|8, 5H9 and are held in normal position by springs 526. If because of improper timing the link 3|!) moves forwardly or rearwardly in such a manner that one of the blocks strikes one of the switch rods 512, it will simply tip and will not cause damage.

In order to cause the slide rod 562 to reciprocate vertically, it is connected by a yieldable link arrangement 521 to one end of a lever 528 pivoted in an ear 536 secured to the frame, the other end of the lever being connected to an arm 532 carrying a cam roll 534 (Figs. 6 and 13) on its opposite end. The cam roll is held in engagement with a cam surface 536 on the cam disk 336 by a spring 536 (Fig. 2) connecting the lever 526 and a pin 546 on the frame of the machine. The cam surface 536 is so related to the picker actuating cams 362, 334 that it causes the switch mechanism tomove .downwardly and to return while the presser foot 66 and the suction cups 66 are in engagement with the forward blank in the magazine. If there is an adequate supply of blanks in the magazine, the switch 464 will remain in the position shown in Fig. 17. That is, the switch rod 5E3 will strike the block 523 and will not move the switch 494 out of its open position. If, however, the picker mechanism is compelled to reach rearwardly a greater distance into the magazine in order to grip a blank, the link 3) will bring the block 522 into position underneath the switch rod 5l2. When the cam surface 555 causes the slide rod 542 to move downwardly, the switch rod 5l2 strikes the block 522 and tips the switch, thus closing the circuit and setting the slow speed motor in operation. The switch will remain in this position until the picker mechanism moves rearwardly to grip a blank such a short distance that the block 523 is brought into position beneath the switch rod 553, thus opening the circuit.

Control devices To stop the machine in case of jams caused by the deviation of a box blank from its proper line of travel, there are provided two control I devices. Referring to Figs. 19 and 20 the first of these devices is operated by the gear 396 on the shaft 392, which drives the shuttle operating lever 312, and comprises a bushing 542 keyed to the shaft and having formed integral with it a plate or flange 544. This plate is provided with a shouldered portion 546 on which is mounted a ring 548. The ring has secured to it a number of pins 558 each surrounded by a spring 552 acting between a recess 554 in the plate 544 and a washer 556 secured on the end of the pin. The spring thus holds the ring 548 close against the plate 544 but permits it to be moved away from the plate when the pin 550 is pressed. Separation of the ring 548 and the plate 544 is accomplished by a number of rivet heads 558 which are secured in a recess 568 in the gear 386. By this arrangement, if the gear 396 rotates relatively to the plate 544, the rivet heads 558 strike the rounded ends of the pins 550 and cause them to push the ring 548 away from the plate 544. As the ring 548 moves away from the plate 544, it strikes a roll 562 carried by the arm 564 of a switch 566 normally held in closed position by a spring 568, and opens the switch.

Movement of the ring 548 axially of the shaft 392 may occur only when there is relative rotary movement between the plate 544 and the gear 396. These parts are normally held against rotation by a shear pin 518 which extends through a sleeve 512 in the gear 396 and into a bore in the plate 544. Apin 514 holds the shear pin in place. The shear pin 518 is provided with a neck 516 which is of smaller diameter than the main portion and which is positioned on the line at which the plate 544 and the gear 396 meet. Thus, if the shuttle in its upward movement meets a twisted blank which resists its movement, the shear pin willbe broken before any of the other parts of the machine are strained suificiently to cause them injury. Breakage of the shear pin 518 will cause the gear 396 to rotate relatively to the plate 544,'thus opening and closing the switch 566 each time one of the rivet heads 558 strikes the rounded head of one of the pins 558.

It may sometimes occur that a blank in either magazine will be moved upwardly out of its proper line of travel as the shuttle rises. In order to prevent damage it is necessary to provide a. mechanism which will stop the machine when this occurs. To this end, a jam detector finger 518 (Figs. 2 and 23) is pivoted on a bracket 580 secured to a plate 582 bolted to the crossbar I I2 of the frame. One end of a link 584 is pivotally connected to the detector finger, the opposite end thereof passing through the end of one arm 586 of a bell crank lever common to the two magazines and pivoted on a projection 588 of the plate 582. Springs 598 surrounding the link 584 between the arm 586 of the bell crank lever and washers 592 provide a yieldable connection b tween the link and the lever, arm. The other arm 594 of the bell crank lever extends over the crossbar I I2 of the frame and rests on the button 596 of a switch 598 which is so arranged that pressure on the button opens the switch. By this arrangemenhif a blank jams and is forced upwardly into the position shown in broken lines in Fig. 23, it strikes the jam detector finger 518 and through the bell crank lever, opens the switch 598.

It is desirable that when the switch 598 of the jam detector or the switch 566 of the shear pin arrangement is open, the entire machine should be stopped. To this end, the control system diagrammed in Fig. 24 is provided. This system comprises an electrically operated switch 688 for controlling the main driving motor 381, a starting circuit 882 for completing the circuit for the winding 684 of the main switch, and a holding circuit 686 which is arranged to be closed by the main switch and to be broken by the switch 598 of the jam detector finger 518 or by the switch 566 of the shear pin mechanism. Starting and stopping switches 666, 689 respectively, and an emergency stop switch 6|8 are also provided in the holding and starting circuits. The main driving motor 381 is operated on 550 volts whereas the conveyor motors 254 and 256 are operated on a smaller voltage. Since it is desirable to stop the conveyor motors when the main driving motor is stopped by one of the safety devices, a relay H2 is provided. This relay is controlled by the main driving motor circuit and is so arranged that When that circuit is closed, the circuits to the conveyor motors are also closed, but opening of the main driving motor circuit will cause the conveyor motor circuits to be opened also.

By the arrangement outlined above, closing the starting switch 688 closes the starting circuit 692 and energizes the winding 684 to close the main switch 688 and therefore the holding circuit 686 for said main switch after the starting button has been released. Depression of the stop button or the momentary opening of any of the switches 566, 598, or 618 will, however, break the holding circuit and thus cause the main switch to be opened. Opening or closing of the main switch 608 which controls the main motor circuit will operate the relay 612 and open or close the circuits to the conveyor motors 254 and 258.

It will frequently be found desirable to stop the production of boxes without action by the operator after a predetermined number of blanks have passed through the machine. This may conveniently be done by shutting off the suction of the suction cups 68. To this end, there is provided a valve 6! (Fig. 22) which has a vertically slidable piston H6. The upper end of the piston is connected to the core 6H3 of a solenoid 628 connected to an indicator mechanism 622 of the type disclosed in Letters Patent of the United States No. 2,040,027, granted May 5, 1936, on the application of Frank E. Northrop. The inclicator 622 is provided with two sets of indicator disks, one set 624 being arranged so that it may be set in accordance with the number of boxes which it is desired to produce, before the machine is stopped. The other set 626 is arranged to indicate the number of blanks that have been taken out of the magazine by the picker and is actuated by an indicator arm 628 connected by a rod 638 to an arm 632 secured to the picker arm shaft 64. Thus, every time this shaft rotates to swing the picker armfcrward and cause a blank to be gripped, the indicator arm 623 is moved, thereby actuating the indicator disks 626. When the two sets'of disks 624, 626 coincide, they open a switch in the indicator 622 through which the circuit 634 for the winding of the solenoid 628 passes, thus causing the solenoid to release the core 6! and close the slide valve M4. The machine will then continue to run butthe picker mechanism will not remove any more blanks from the magazine until the indicator mechanism has been reset. The solenoid circuit 634 receives current through the contacts of the relay 6H! controlling the conveyor motors, and when the relay 6l2 opens the latter circuits, it also opens the solenoid circuit 634, shutting off suction at the valve BIG.

Operation Inasmuch as the function of each of the various portions of the machine has been described in detail in connection with the description of its mechanisms, only a brief description of the operation of the machine is believed to be necessary. The packs of blanks which may, of course, be of different sizes are placed between the pack supporting rods 55 of the conveyor withtheir edges resting on the table 52, and are moved by said rods into the magazine B. As each pair of rods reaches the magazine, it is lowered out of pack separating position by the lever 66, another pair of rods being raised simultaneously at the leading end of the conveyor. anism then swings rearwardl'y, and with the presser foot 66 resting against the forward face of the leading blank in the magazine to hold it in place, the suction cups 68 grip the lower edge of the blank and roll it forwardly over the retaining member HQ. If the pair of suction cups on one side of the machine fails to grip the blank at this point, the reduction in the amount of suction caused by the partial closing of the cam-actuated suction valve 344 will prevent the suction cups of the other side of the machine from pulling a blank from the magazine, thus insuring that an equal number of boxes and box covers will be fed to the operating mechanisms. With the blank in this condition, and with its upper edge pulled downwardly slightly out of engagement with the stop Hi], the separators iii are raised to complete the separation of the blank from its pack. If, in their upward movement the separators strike a broken or distorted blank which interferes with upward movement, the shear pin 570 breaks, opening the switch 566, and stopping the machine. Similarly, if a blank catches on one of the separators and is forced upwardly out of its normal path, it strikes the jam detector finger 513, opening the switch 598 and stopping the machine. At the top of the stroke of the separators It), the catches I2 slip over the top edge of the blank, and on the return movement of the separators, the blank is slid downwardly between the carrier wheels M and the guides H3. A pair of lugs 13 moves the blank about the carrier wheels and between the guides 89 and the carrier wheels 82 in position to be engaged by the lugs 86 of the-chains 8d which carry it upwardly and onto the rails 88. This operation is repeated with successive blanks until the switch in the indicator 622 is opened by the passage of the desired number of blanks through the machine, thus shutting off the suction in the suction cups 68.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a sheet feeding apparatus, a magazine, an endless chain having a path of movement toward and away from said magazine, a plurality of rods carried by said chain and movable longitudinally of themselves in said chain, means. for supporting said rods in ack supporting position during their movement toward the magazine, and means for shifting said rods out of pack'supporting position at the end of their movement toward said magazine.

2. In a sheet feeding apparatus, a pair of con- The picker mech- H veyor chains positioned one above the other, a plurality of rods carried by said chains and movable lengthwise of themselves in said chains, and means for moving said rods lengthwise of themselves at one end of said chains.

13. In a sheet feeding apparatus, conveyor means including a pair of endless chain positioned one above the other, a plurality of rods slidably carried by said chains for heightwise movement therein and constructed and arranged to hold a number of packs of sheets in spaced relation to one another, means for raising said rods to pack engaging position at one end ofthe conveyor, and means for lowering said rods out of pack engaging position at the other end of said conveyor.

4. In a sheet feeding apparatus, a sheet magazine, a pair of endless chains positioned one above the other, said chains having a path of movement toward and away from said sheet magazine, a plurality of rods slidably carried by said chains for heightwise movement therein, a high track along which said rods may slide toward the magazine when in raised position, a low track along which said rods may slide away from the magazine when in lowered position, means for raising said rods at the loading end of said chains, and means for lowering said rods at the magazine end of said chains. v

5. In a sheet feeding apparatus, conveyor means, means for holding a plurality of packs of sheets on edge in spaced relation to one another on said conveyor means, and means including a lever for retracting said holding means from pack holding position.

6. In a sheet feeding apparatus, conveyor means including a plurality of members for holding a number of packs of sheets on edge in spaced relation to one another, a lever, means for rocking said lever about its fulcrum point, means carried by one end of said lever for raising one of said holding members into pack supporting position, and means carried by the other end of said lever for forcing one of said holding members out of pack supporting position.

7. In a sheet feeding apparatus, conveyor means including a plurality of retractable pack engaging members, said members being constructed and arranged to hold a number of packs of sheets on edge in spaced relation to one another, means including a lever for simultaneously moving one of said pack engaging members into pack engaging position at one end of said conveyor and moving another of said pack engaging members out of pack engaging position at the other end of said conveyor, and means for driving said conveyor means and for moving the pack engaging members in timed relation to one another.

8. In a sheet feeding apparatus, conveyor means including a plurality of retractable pack engaging members, said members being constructed and arranged to hold a number of packs of sheets on edge in spaced relation to one another, means including a lever for moving one of said pack engaging members out of pack engaging position at one end of said conveyor, a crank for operating said lever, and means for driving said crank in timed relation to the movement of said conveyor.

9. In a sheet feeding apparatus, conveyor means including a plurality of retractable pack engaging members constructed and arranged to hold a number of packs of sheets on edge in spaced relation to one another. a sheet magazine, means for advancing said conveyor means to replenish the supply of sheets in said magazine, and separate means for advancing said conveyor means at a greater rate of speed to close th gaps between successive packs of sheets as they are about to be carried into the magazine.

10. In a sheet feeding apparatus, means for advancing a number of packs of sheets to a delivery point in spaced relation to one another, and means for increasing the rate of advance of said packs as each pack nears said delivery point thereby to close the spaces between said packs.

1*1. In a sheet feeding apparatus, means including a plurality of retractable Pack separating members for conveying a number of separate packs to a delivery point, and means for advancing said conveyor means at a relatively high rate of speed as each pack nears said delivery point thereby to close the spaces between said packs.

12. In a sheet feeding apparatus, conveyor means including a plurality of retractable pack engaging members constructed and arranged to s iDDOrt a number of separate packs of sheets on edge in spaced relation to one another, a sheet magazine, means for picking successive sheets from said magazine, and means controlled by said picking means for advancing the conveyor means to replenish the supply of sheets in the magazine.

13. In a sheet feeding apparatus, a magazine, conveyor means constructed and arranged to carry to the magazine a number of packs of sheets in spaced relation to one another, means for picking successive sheets from said magazine, means controlled by said picking means for advancing said conveyor means, and means opera tive when there is a gap between the rearmost blank in the magazine and the foremost blank of the next succeeding pack to advance said conveyor means at a higher rate of speed.

14. In a sheet feeding apparatus, conveyor means constructed and arranged to carry to a magazine a number of packs of sheets in spaced relation to one another, means for picking successive sheets from said magazine, means adjacent to said magazine for detecting gaps between the rearmost blank in the magazine and the adjoining pack of sheets, and means controlled by said detector means for advancing said conveyor.

15. In a sheet feeding apparatus, means for r" advancing a plurality of packs of sheets in spaced relation to one another to a delivery point, a finger for detecting spaces between said packs at said delivery point, and means controlled by said finger for setting said advancing means in operanon.

16. In a sheet feeding apparatus, conveyor means constructed and arranged to carry to a magazine a number of packs of sheets in spaced relation to one another, means oscillatable toward and away from said magazine for picking successive sheets from said magazine, and means controlled by the extent of oscillatory movement of said picking means for advancing said conveyor means. I

17. In a sheet feeding apparatus, a magazine, means for advancing sheets into the magazine at one side, means movable toward and from the opposite side of the magazine for picking oif successive single sheets, and means controlled by the extent of movement of the picking means for controlling the sheet advancing means.

18. In a sheet feeding apparatus, conveyor meansfiir advancing sheets to a delivery point,

movable means fol picking on sheets 'at said dremoving successive sheets from said magazine, means for advancing said conveyor, other means livery point, an electric motor for driving said conveyor means, a switch for the motor, and means constructed and arranged to operate said switch when the picking means moves beyond predetermined limits.

19. In a sheet feeding apparatus, conveyor means for advancing sheets to a delivery point, means for picking off successive sheets at said delivery point, said picking means being mounted for swinging movement toward and away from said delivery point, means for swinging said picking means, drive means for said conveyor means, a switch for said drive means, and means carried by said swinging means constructed and arranged to operate said switch when the picking means swings beyond predetermined limits.

20. In a sheet feeding apparatus, conveyor means for advancing sheets to a deli ery point, means for picking off successive sheets at said delivery point, said picking means being mounted for swinging movement toward and away from said delivery point, means for swinging said picking means, drive means for said conveyor means,

a tiltable mercury switch for said drive means, and means carried by said swinging means and constructed and arranged to .cause said switch to be tilted when the picking means swings beyond predetermined limits.

21. In a sheet feeding apparatus, means for advancing sheets to a delivery point, means for gripping successive sheets at said delivery point, means for moving said gripping means toward and away from said delivery point, drive means for said sheet advancing means, a switch forsaid drive means, switch control means oscilla'table toward and away from said gripper moving means, and means carried by said gripper moving means constructed and arranged to operate said switch control means when said gripping means moves beyond predetermined limits.

22. In a sheet feeding apparatus, conveyor means for feeding successive spaced packs of sheets into a magazine, an oscillatory picker for for advancing said conveyor at a greater rate of speed than that of said first-mentioned conveyor advancing means, mean responsive to the extent of oscillatory movement of said picker for controlling said first-mentioned advancing conveyor means, and means responsive to the gaps between said packs for controlling the highspeed conveyor advancing means. r

23. In a sheet feeding apparatus, a magazine for holding a plurality of sheets on edge in a horizontal stack, said magazine comprising yieldable members for limiting the forward movement of sheets in said magazine, displaceable members against which the sheets in the magazine are urged by said yieldable members, and means for inserting additional sheets into said magazine by movement past said displaceable members.

24. In a sheet feeding apparatus, a sheet magazine, means for shifting the forward, sheet of a stack in said magazine in a direction substantially normal to the face of said sheet to a position spaced apart from. the stack, delivery means, and means engaging the edge of said sheet for moving said sheet in a direction substantially parallel toits face to present it to said delivery means. e

25. In a sheet feeding apparatus, a sheet magazine, delivery means, reciprocatory means movable in one direction to shift the forward sheet of a stack in the magazine in a direction substantially normal to the face of said sheet to a position spaced apart from the stack, and means carried by said reciprocatory means for engaging the edge of said sheet whereby the return movement of said recipr-ocatory means moves the sheet in a direction substantially parallel to its face to present it to the delivery means.

26. In a sheet feeding apparatus, a magazine for a stack of sheets, means movable between the forward sheet in said magazine and the remainder of the stack for separating said forward sheet from the stack, delivery means, and means carried by said separating means for engaging the edge of the separated sheet to transfer it to said delivery means.

27. In a sheet feeding apparatus, means for separating one side of the forward sheet of a stack from the remainder of the stack, a member constructed and arranged to complete the separation of the forward sheet from the stack, delivery means, and means associated with said member and movable thereby into engagement with the opposite edge of the sheet from the delivery means for transferring said sheet to said delivery means.

28. In a sheet feeding apparatus, means for bending one edge of a sheet in a stack away from the remainder of the stack, and means movable between said stack and said sheet and provided with a yieldable projection arranged to engage and complete the separation of said sheet from said stack.

29. In a sheet feeding apparatus, a sheet magazine, means including a suction member and a presser foot for bending one edge of the forward sheet in said magazine away from the stack therein, a separator for completing the separation of the forward sheet from the stack in the magazine, delivery means, and means carried by the separator for transferring said forward sheet to the delivery means,

30. In a sheet feeding apparatus, a sheet magazine, means for separating one side of the forward sheet in said magazine from the stack therein, means for successively removing individual sheets from said stack comprising a mem-- ber reciprocable in a direction substantially paral'lel to the planes of the sheets in said stack and constructed and arranged to complete the separation of the forward sheet from the stack in the magazine, and an element carried by said member adapted to engage one edge of the foremost sheet in said stack to slide the same out of said magazine when said member is moved in one direction.

31. In a sheet feeding apparatus, a plurality of rotative carrier members having projections thereon and constructed and arranged to move a sheet to a delivery point, and means for advancing a sheet to said carrier members.

32. In a sheet feeding apparatus, a sheet magazine, means for removing a sheet from said magazine, a conveyor, a plurality of rotative carrier members, and means carried by said carrier members for engaging the sheet thereby to de- I liver it to said conveyor. 7

33. In a sheet feeding apparatus, a sheet magazine, a member for separating the forward sheet in said magazine from the stack therein. a sheet conveyor, a carrier wheel for delivering the sheet to said sheet conveyor, and means carried by the separating member for presenting said forward sheet to said carrier wheel.

34. In a sheet feeding apparatus, a sheet magazine, means for separating the forward sheet in the magazine from the stack therein, a sheet conveyor, a carrier wheel having peripheral lugs and constructed and arranged to receive a sheet and to deliver it to said conveyor, and means carried by said separating means for presenting said forward sheet to the carrier wheel.

35. In a sheet feeding apparatus, a sheet magazine, a shuttle for separating the forward sheet in said magazine from the stack therein, means carried by said shuttle for sliding the leading sheet out of the magazine, a pair of carrier wheels having a plurality of peripheral sheet engaging members, and means for holding a sheet in position to be engaged by said sheet engaging members as the wheels are rotated.

36. In a sheet feeding apparatus, a sheet magazine, a shuttle for separating the forward sheet in said magazine from the stack therein, means carried by said shuttle for sliding the leading sheet out of the. magazine, a carrier wheel, a second carrier wheel, and a conveyor chain passing about said second wheel and constructed and arranged to receive a sheet from said second wheel.

37. In a sheet feeding apparatus, means for picking a sheet from a stack, delivery means, means for transferring a sheet from said picking means to said delivery means, means for driving said picking and said transferring means, and means including a breakable member in said driving means constructed and arranged to stop said driving means when the picking or the transferring means jams.

38. In a sheet feeding apparatus, sheet advancing means, means including a gear for driving said sheet advancing means, a member rotatable with said gear, a breakable member connecting said gear and rotatable member, and

' necting member for stopping said driving means,

39. In a sheet feeding apparatus, sheet advancing means, means including a gear for driv-,

ing said sheet advancing means, a member rotatable and coaxial with said gear, a shear pin connecting said gear and said member, means for moving said member axially away from said gear upon breakage of the shear pin, and means constructed and arranged to stop said driving means when the member moves axially away from the gear.

40. In a sheet feeding apparatus, a magazine, means for conveying packs of sheets to' said magazine, a drive for said conveyor, means for picking a sheet from the magazine, delivery means, means for transferring a sheet from the picker means to the delivery means, means for driving the picker and the transferring means, a readily breakable member in one of said drive means, and means operable upon the breakage of said member for stopping both of said drive means- 41. In a sheet feeding apparatus, sheet advancing means, a switch for said means, delivery means, means including a breakable member for driving said delivery means, a switch for said driving means, means operable upon the breakage of said breakable member to open said switch for said delivery means, and a relay controlled by said delivery means switch for opening the switch controlling the sheet advancing means.

42. In a sheet feeding apparatus, sheet advancing means, means including a gear for driving said sheet advancing means, a member rotatable and coaxial with said gear, a shear pin connecting said gear and said member, means for moving said member axially away from said gear upon breakage of the shear pin, a switch for said drive means, and a switch arm constructed and arranged to open said switch when said member moves axially away from the gear.

43. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means for picking a blank from the box blank magazine, means for picking a blank from the cover blank magazine, and means for preventing only one of said picking means from taking a blank from its respective magazine.

44. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means for picking a blank from the box blank magazine, means for picking a blank from the cover blank magazine, and means for causing One of said picking means to release its blank if the other picking means fails to pick a blank from its magazine.

45. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means including a suction member for picking a blank from the box magazines, means including a suction member for picking a blank from th cover blank means, and means for controlling the suction in said members, said means being constructed and arranged to render the suction in one member insufficient to hold a blank if the suction member of the other picking means fails to hold a blank.

46. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means including a suction member for picking a blank from the box magazine, means including a suction member for picking a blank from the cover blank means, means for initially evacuating the air from said suction members thereby to grip the forward sheets in said magazines, and means for reducing the rate of evacuation of air from said members after the initial contact of said members with their respective blanks.

4'7. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means including a suction member for picking a blank from the box magazine, means including a suction member for picking a blank from the cover blank magazine, and means for controlling the amount of suction of said members, said means being constructed and arranged to effect a relatively high initial suction and, subsequently, to reduce the amount of suction to a point where it is insuflicient to hold a blank unless allthe members are holding blanks.

48. In a box making machine, a magazine for box blanks, a magazine for box cover blanks, means including a suction member for picking a blank from the box magazine, means including a suction member for picking a blank from the cover blank magazine, a pump for withdrawing air from said members, all of said members being connected to said pump, and means for controlling the rate of evacuation by said pump, said means being constructed and arranged to reduce the rate of evacuation to a point where it will not maintain suflici'ent vacuum to hold a blank against one of said members unless all of said members are covered by blanks.

49. In a box making machine, a magazine for box blanks, a magazine for cover blanks, means including a suction member for picking ablank from the box magazine, means including a suction member for picking a blank from the cover blank magazine, a pump for withdrawing air from said members, all of said members being connected to said pump, a valve, and a cam operative in timed relation to said picking means for controlling said valve, said cam being constructed and arranged to open said valve and subsequently to partially close it.

50. In a box making machine, a magazine for box blanks, a magazine for cover blanks, means including a suction member for picking a blank from the box magazine, means including a suction member for picking a blank from the cover blank magazine, a pump for withdrawing air from said members, all of said members being connected to said pump, and a valve mechanism constructed and arranged to open when said suction members engage the blanks in the magazines and thereafter partially to close, thereby to reduce the rate of withdrawal of air from said members to a point where it is insufficient to hold a blank unless all of said members are holding blanks.

51. In a sheet feeding apparatus, a magazine, means for picking a sheet from said magazine, means actuated by the picker means for registering the number of sheets picked thereby, and means controlled by the register means for preventing more than a predetermined number of sheets from being withdrawn from the magazine.

52. In a sheet feeding apparatus, a sheet magazine, means including a suction member for picking a sheet from said magazine, a valve by which the suction is governed, means controlled by the suction member for registering the number of sheets withdrawn from said magazine, and means controlled by said register means for actuating the valve.

53. In a sheet feeding apparatus, a magazine, means including a suction member for picking a sheet from said magazine, means controlled by the picker means for registering the number of sheets withdrawn from the magazine, a pump connected to said suction member and constructed and arranged intermittently to create a partial vacuum in said suction member, a valve for disconnecting said pump from said suction member, and electrical means constructed and arranged to close said valve when a predetermined number of sheets have been removed from the magazine.

54. In a sheet feeding apparatus, a magazine, means including a suction member for removing a sheet from said magazine, means for creating a partial vacuum in said suctionmember, avalve for controlling said vacuum creating means, electrical means for operating said valve, and means for controlling the valve operating means, said last-named means comprising a setting device and a counter for counting the operations of said removing means, said setting device said counter being arranged to actuate said electrical means when their indications correspond.

55. In a sheet feeding apparatus, a sheetconveyor, a magazine receiving sheets from the conveyor, means for picking a sheet out of said magazine, and means operative when sheet moves out of its proper line of travel through the apparatus for shutting off the conveyor and the picker means.

56. In a sheet feeding apparatus, a sheet-conveyor, a magazine receiving sheets from the conveyor, means'for picking the forward sheets from said magazine, delivery means, means for trans- 

